Screw conveyors are a cornerstone of efficient bulk material handling. These versatile machines use a rotating screw shaft within a trough to efficiently move materials across horizontal, inclined, or even vertical distances.
But with so many variations available, selecting the right type of screw conveyor for your operations can seem daunting.
That’s why we created this guide.
Now, you’ll have a better understanding of the most common types of screw conveyors and be equipped to identify the one best suited to your needs.
Understanding Screw Conveyor Basics
At their core, all screw conveyors share a similar design principle. A helical screw flight rotates within a trough, continuously pushing material along its path.
The material enters at the infeed end and exits at the discharge outlet.
But, one of its main benefits lies in the various configurations that cater to specific material properties and conveying requirements.
Shafted Screw Conveyors: The Workhorses of Material Handling
Shafted screw conveyors are the most widely used type.
They consist of a screw shaft with a helical flight pattern enclosed within a U-shaped or tubular trough.
As the screw rotates, the material is pushed along the trough towards the discharge outlet.
Shafted screw conveyors are ideal for:
- Horizontal conveying. They excel at efficiently moving materials across horizontal distances.
- Inclined conveying. For applications requiring material movement at an angle, shafted screw conveyors can be inclined up to a certain degree (typically around 45 degrees). Steeper inclines may require a different type of conveyor due to reduced efficiency and increased risk of material rollback.
- A wide range of materials. Shafted screw conveyors can handle a diverse range of bulk materials, from free-flowing powders to slightly sticky materials. Volumetric feeders, a specific type of shafted screw conveyor, excel at delivering precise and controlled material flow rates.
Vertical Screw Conveyors: Taking Up Less Space
As the name suggests, vertical screw conveyors are designed to elevate bulk materials in a vertical direction efficiently.
They feature a tightly coiled screw within a vertical housing.
Material enters at the bottom and is steadily pushed upwards by the screw rotation for discharge at the top.
Vertical screw conveyors offer several advantages.
- Space-saving design. They require minimal floor space compared to bucket elevators or other vertical conveying methods.
- High efficiency. The enclosed design minimizes material spillage and dust generation.
- Gentle product handling. The vertical screw flight minimizes the degradation of fragile materials during conveying.
Vertical screw conveyors are well-suited for applications such as:
- Transferring materials between different processing levels.
- Feeding materials into storage silos or mixing vessels.
Beyond the Basics: Specialized Screw Conveyor Designs
While shafted and vertical screw conveyors cover most applications, there are additional specialized designs to consider.
Shaftless Screw Conveyors
These innovative conveyors eliminate the center shaft, allowing easier cleaning and material changeovers.
They are ideal for sticky materials that might bind on a traditional screw shaft.
U-trough vs. Tubular Trough
Shafted conveyors typically come in U-shaped or tubular troughs.
- U-troughs offer easier access for cleaning and material inspection.
- Tubular troughs provide a more streamlined design for enclosed environments.
Choosing the Right Type of Screw Conveyor
Selecting the optimal screw conveyor depends on several factors.
- Material type and characteristics. The flowability, particle size, and potential abrasiveness of your material will influence the type of screw and trough design needed.
- Conveying capacity and distance. The required throughput and conveying distance will determine the screw size and motor power needed.
- Inclination angle (if applicable). For inclined applications, the angle of incline and material properties will dictate whether a shafted screw conveyor is suitable.
- Integration with existing equipment. Ensure the chosen screw conveyor can seamlessly integrate with your existing production line layout and equipment.
Need a Screw Conveyor Solution?
Look no further than ISC Manufacturing!
We are experts in designing and manufacturing high-quality screw conveyors. Our team of engineers can help you select the ideal type of screw conveyor for your specific needs, ensuring optimal performance and efficiency within your operation.
We offer a wide range of screw conveyor designs, materials, and capacities to suit any application.
Contact us today to discuss your project requirements and explore how our custom-engineered screw conveyors can optimize your bulk material handling.
